With the development of computer technology, modern CNC offline diagnostic software is gradually being integrated with CNC control software. Some systems have introduced "expert systems" into fault diagnosis, which undoubtedly brings convenience to the maintenance and diagnosis of CNC machining centers. Through such software, the operator can diagnose the fault of the CNC system or machine tool by simply doing some simple conversation operations on the CNC's offline diagnostic software.
The following are the self-diagnosis methods provided by ETCN.
Power-on self-diagnosis is a diagnosis that is automatically executed by the system's internal diagnostic program when the index control system is powered on. It is similar to the boot diagnosis of a computer. The startup self-diagnosis of CNC machining center can automatically check the key hardware devices in the system and determine the installation, connection status and performance of the specified equipment. Some systems can also diagnose some important chips.
Online monitoring can be divided into two forms: the internal program monitoring of the CNC machining center and the monitoring through external equipment. CNC internal program monitoring is a method of automatically diagnosing, checking and monitoring the status of each part through the internal program of the system. The scope of online monitoring includes the CNC itself and the servo unit, servo motor, spindle servo unit, spindle motor, external equipment, etc. connected to the CNC machining and manufacturing. Online monitoring is always effective during the working process of the system. The internal program monitoring of the numerical control system includes three aspects: interface signal display, internal status display and fault display.
1. CNC machining center interface signal display
It can display the current status of all interface signals between CNC and PLC, CNC and machine tool. Indicate the on-off status of digital input/output signals to help analyze failures. When repairing, you must understand the meaning of each signal between CNC and PLC, CNC and machine tool, as well as the various conditions for signal generation and cancellation, so that you can perform corresponding inspections. The "function manual" and "connection manual" provided by CNC manufacturing company and the "machine tool electrical schematic diagram" provided by CNC manufacturing companies are technical guidelines for the above state inspection.
2. Internal status display of CNC machining center
Generally speaking, using the internal status display function, you can display the following aspects: External reasons that cause the cycle instruction (processing program) to not be executed.
For example: Whether the CNC machining center system is in the "in-position check"; whether it is in the "machine lock" state; whether it is in the "waiting for speed arrival" signal is turned on; whether it is waiting for the "position encoder" when programming the feed per revolution of the spindle Measurement signal; what happens during thread cutting, etc.
3. CNC machining center fault information display
In the numerical control system, the fault information is generally displayed on the CRT in the form of "alarm display". The content of the alarm display differs depending on the CNC system. Most of this information appears in the form of "alarm number" plus text. The specific content and troubleshooting methods can be consulted on the "maintenance manual" provided by the CNC system manufacturer. Monitoring through external equipment refers to the use of computers, PLC programmers and other equipment to automatically diagnose, inspect and monitor the status of each part of the CNC machining center CNC machine tool.